Background Sexual behavior during travel has increasingly become a focus of travel medicine research. The perceived freedom when away from home can lead to increased casual sexual activities, often unprotected. Local sexual partners, particularly those who are in close contact with tourists due to their occupation, need to be considered more in research. The purpose of this study was to explore the sexual behavior, knowledge of STI prevention, and prevalence of serum markers of selected STIs in tour guides in Cuzco/Peru.

Methods In this cross-sectional study, 161 tour guides completed a questionnaire consisting of information on demographics, sexual behavior, and knowledge about STI prevention. Blood samples of the participants were tested for antibodies against HSV2, Chlamydia trachomatis, and Treponema pallidum using commercial enzyme-linked immunosorbent assay kits.

Results The majority of guides (65%) were sexually active during the year prior to the study and 10% had foreign partners. Consistent condom use was reported by 38.1%, but almost 42% did not use condoms. In total, 27.6% reported symptoms compatible with STI. Three quarters of the participants had previously received information on STI prevention, predominantly from health professionals. In total, 22% considered themselves at high risk for STI. Antibodies against C trachomatis were prevalent in 15%, while 88.2% were against HSV2. None had antibodies against T pallidum.

Conclusions There is an inconsistency in reported sexual behavior and reported knowledge about STI prevention. Because of the tour guides’ bridging position between potential STI carriers in tourists and the local population, the reported nonuse of condoms is of concern. The prevalence of serum markers supports this concern, which is aggravated by the potential of noncurable infections. Current sexual health education strategies seem unsatisfactory, and major modifications are highly recommended.